1. Field of the Invention
The present invention relates to a hot water tank for heating water, and, more particularly, to a hot water tank for heating water which includes means for transforming a high velocity jet of incoming cold water at the inlet of the tank to a low velocity-high volume flow or piston for forcing hot water accumulated in the upper portion of the tank through the outlet, whereby turbulent mixing between the incoming cold water and the accumulated hot water is minimized and outlet water mixing can be precisely set.
2. Description of Related Art
In any hot water heating system, the heated hot water is forced out of the heating container by the displacement of that hot water by inlet cold water. With respect to smaller tanks (on the order of 1.5 liters), this introduction of cold water causes turbulent mixing between the cold water and hot water, where the end result is that water neither hot nor cold (but at a temperature therebetween) is provided at the outlet. Ideally, the hot water should be forced out of the tank by a "piston" of cold water, which is defined as a low velocity-high volume flow of water under fluid pressure that emanates from the bottom of the tank to the top.
While there are several references in the art which disclose designs for water heaters that combat the effects of sediment in the bottom of the tank (e.g., U.S. Pat. No. 4,838,211 to Vago and U.S. Pat. No. 4,257,355 to Cook), there has been relatively little done to minimize the turbulent mixing of cold water and hot water stemming from the introduction of cold water into the tank. U.S. Pat. No. 2,644,432 to Hummel, however, discloses a hot water tank having a horizontal orientation which includes a first baffle positioned above the inlet to cause water directed across the tank to spread laterally and spill out from under deflecting plates attached to each side of the baffle, as well as a second baffle partition which extends substantially horizontally across the tank to divide it into upper and lower sections. The second baffle partition allows communication between the upper and lower sections of the tank through either a single opening or a plurality of grouped holes or openings arranged at one end of the tank remote from the water inlet. It should be understood that while U.S. Pat. No. 2,644,432 has an object similar to that of the present invention, the prevention of free circulation between cold water entering at the inlet of the bottom of the tank and hot water in the upper portion thereof, the baffle design in the '432 patent is very crude and relies principally upon the first baffle to reduce turbulent mixing caused by the incoming water. Thereafter, water is allowed to rise in the tank and through the second baffle partition in a general convection flow as it is heated.
Accordingly, a primary objective of the present invention is to provide a hot water tank which includes means for transforming a high velocity jet of incoming cold water at the inlet of the tank to a piston for forcing hot water accumulated in the upper portion of the tank through the outlet.
Another objective of the present invention is to provide a bypass means for allowing a portion of the inlet cold water jet to be routed to a mixing orifice and mixed with outgoing hot water to increase the actual volume of hot water exiting the tank.
A further objective of the present invention is to minimize the variance in water temperature at the outlet of the hot water tank.
Still another objective of the present invention is to provide a distribution baffle which transforms a high velocity water jet introduced at its inlet side to a low velocity-high volume flow on its outlet side.
Yet another objective of the present invention is to provide means for attaching the distribution baffle in the hot water tank so as to satisfy Food & Drug Administration and National Sanitation Foundation regulations.
These objectives and other features of the present invention will become more readily apparent upon reference to the following description when taken in conjunction with the following drawing.